Birds have songs, to attract partners and defend territories, and calls, for different situations such as alarm, begging etc. In chaffinches, males have a special call, that is called "rain-call" in different languages. The rain-call is proposed to have the same function as a song, and be emitted instead of songs during bad weather conditions, but the origin of this belief is unknown.
With students, we checked whether the rain-calls were emitted instead of songs more often when it rained. We installed about 50 automatic recorders in gardens and observed additionally 509 wild chaffinches in forests, but we did not find any relations between the weather conditions and chaffinch vocalizations.
However, we found that raincalls were much more frequent when a female was close to the rain-calling male, therefore, we propose that this call has a function in mate attraction. We hope that this project help us understand the communication system of one of the most common bird species in Europe, and we are happy that this project helped raise attention for common birds in urbanized areas. In our garden recordings, we also identified 67 other species calling and singing in the gardens near Munich!
Below, you will find our flyer (in German) that we used to promote our study among garden owners. And here is a link to the published scientific article.
Photo: a Male chaffinch singing in a plum tree, picture by F. Bénard.
